Computing devices, such as mobile phones, tablet devices, laptop computers and any other communication-enabled devices wirelessly communicate with access points, such as implemented in a Wi-Fi network. A mobile computing device is commonly referred to as a client device or “station” in a Wi-Fi network. Generally, a station may be any portable, mobile, or fixed computing device designed to be IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi) compliant with a media access control (MAC) and physical layer (PHY) interface for wireless communication. A station communicates with an access point that is within communication range in the Wi-Fi network.
Generally, an access point, such as may be implemented in a router device, provides network connectivity for a Wi-Fi compliant device, such as a fixed or mobile computing device. Additionally, access points typically have a greater communication range than do the stations, which may vary in power-level capabilities, some being high-end stations with more of a communication range and others being low-end stations with less of a communication range. However, all of the stations need to be able to associate and communicate with an access point to enable wireless communication on the Wi-Fi network.
An access point may implement the single user (SU) sequential polled acknowledgement technique as provided for in IEEE 802.11ac, where multiple stations that receive a downlink multi-user (DL MU) transmission from the access point respond to the access point in sequential order. For sequential acknowledgement, only one of the multiple stations that is the recipient of the DL MU PPDU (PLCP (PHY Layer Convergence Procedure) Protocol Data Unit) from the access point can solicit an acknowledgement (ACK). The data frame for one station will set its acknowledgement policy (the AMPDU (Aggregated-MAC Packet Data Unit)) as an immediate ACK while the data frames for other stations will be set as a block acknowledgement (BA) (i.e., AckPolicy “11” in QoS control field). In other words, each of the other stations will respond to a BlockACK Request (BAR) frame in sequential order.
Alternatively, an access point may implement a multi-user (MU) acknowledgement technique, such as provided for in the new IEEE 802.11ax protocol for High Efficiency WLAN (Wireless Local Area Network) (HEW). The access point can communicate a downlink high efficiency multi-user (HE MU) PPDU, soliciting an acknowledgement from multiple stations that support uplink OFDMA (Orthogonal Frequency-Division Multiple Access), such as in the new IEEE 802.11ax protocol. Communication efficiencies are improved with this association technique that provides parallel transmission for multiple stations. More than one station can solicit an immediate acknowledgement (i.e., each AMPDU has an QoS AckPolicy “01” in QoS control field), and each ACK/BA from the recipient stations is transmitted in independent resource units (RU).